This invention relates to a sheet arranging system for use with a sorter, collator, etc., wherein sheets fed on the basis of a rearward reference are moved toward a forward reference edge disposed parallel to the direction of travel of the sheets, to arrange the sheets in accordance with the forward reference.
When copying is carried out by means of an electrophotographic copying apparatus, a method for placing an original in such a manner that its adjacent two sides are in abutting relation to front and side edges of contact glass is widely used because of the ease with which the operation can be performed. However, an image formed in the exposing step on a photosensitive member is reversed to the image of the original with respect to front and rear and left and right, so that the process steps following the exposing step are carried out in accordance with a rearward reference (as viewed from the operator) and copies are ejected from the copying apparatus in accordance with the rearward reference.
A sorter automatically classifies copies according to pages and is expected to have wide application in the future in offices for automation of office work which has hitherto been performed manually. A sorter includes a plurality of bins arranged in a plurality of layers in superposed relation for receiving copies therein. When copies are stacked in each bin in accordance with the rearward reference, difficulties are experienced for the operator to check them visually and retrive them therefrom, particularly when the copies are small in size, so that it is desirable to process the copies during the process of conveyance and arrange them in accordance with a forward reference.
To this end, it has hitherto been customary to provide an arranging section having a forward reference edge between the inlet rollers and intermediate rollers of the sorter, for example, wherein a copy forwarded in accordance with the rear reference is moved transversely or obliquely into contact with the forward reference edge and arranged in accordance with the forward reference. When a sheet is moved obliquely, the sheet may for some reason be pivotally rotated and makes a "head-on collision" or a corner of the leading edge of the sheet near to the operator may abut against the forward reference edge. When this is the case, the sheet may be bent or if the worst comes to the worst, may be rotated in such a manner that the leading edge of the sheet is disposed along the forward reference edge, due to the drive force of obliquely moving rollers, the force of friction produced between the corner of the sheet and the reference edge and the gravity of the sheet.
A sheet arranging system of the prior art that has been developed to cope with this situation is disclosed in Japanese patent application Laid-Open No. Sho-51-147326, for example, in which two sets of obliquely moving rollers are located parallel to the forward reference edge downstream of the receiving rollers, and the set of obliquely moving rollers nearer to the forward reference edge have a higher component of the peripheral velocity in the direction of regular sheet movement than the other set of obliquely moving rollers, to thereby prevent sheets from making a head-on collision with the forward reference edge irrespective of their size. This system has the disadvantages that they are large in the number of parts and the construction is complex.
Another system is known in which a sheet is placed on a belt mounted obliquely between the receiving rollers and delivery rollers of the arranging section, and the sheet is moved obliquely as it is released from the receiving rollers until one side of the sheet abuts against the forward reference edge when the sheet moves along the forward reference edge and nipped by the delivery rollers. In this system, a belt drive mechanism and other mechanisms of high expenses are used, thereby increasing cost.
A proposal has also been made to use a striking plate for striking a sheet at the rearward edge by the striking plate to cause the sheet to move into contact with the forward reference edge. The aforesaid striking of the sheet should be carried out after the sheet is released from the receiving rollers and before it is nipped by the delivery rollers, so that difficulties are encountered in moving the sheet in good timing.